It is all hypthetical.
We have no idea whatsoever, definitively, how the whole Jesus in the flesh actually worked.
It is unreasonable, in my opinion, to believe that Jesus was ever in the childs body when it was little.
That is absurd. What... God removed all of his intellect somehow, just put it in limbo until he was 12.
Then wait... after realizing he was the SoG, he just hung around for 18 more years??
And then one day... "yeah... maybe I will go preach and die now"
C'mon
God the Father has an immortal body of flesh and bones. Not only Jesus but all of us were created in His image and likeness. Jesus was born of an immortal God who has a body of flesh and bones and a mother who has a mortal body of flesh and bones. Before this world was created, we all existed as the spirit children of God the Father. We all had knowledge of God and sided with him in the war in heaven before the foundation of this earth. Upon being born, God puts a veil over our minds so that we cannot remember our premortal existence and requires that we learn to walk by faith and learn to choose in and of ourselves good over evil and become a good being of our won free will and choice. Jesus was part of the Godhead and submitted his will to the will of the Father. After being born into this life he learned at an early age who he was and again submitted his will unto the will of the Father. Jesus was such an advanced spirit in the premortal existence and was the firstborn spirit child of the Father. He was such and excellent being that he was chosen to be part of the Godhead before the world was. Upon being born into this life he quickly came to know his mission in life and submitting his will to the Father he was to become the Savior of the world as he was chosen to become before the earth was. Jesus thus inherited immortal and mortal qualities. As part mortal and part immortal, he could choose to lay down his life as a sacrifice for sin.
John 10:17-18
17 Therefore doth my Father love me, because I lay down my life, that I might take it again.
18 No man taketh it from me, but I lay it down of myself. I have power to lay it down, and I have power to take it again. This commandment have I received of my Father.
Here we read that no man could take Jesus' life from him. He had to lay it down of his own choosing. Jesus had the choice. He was the only person to live a sinless life. He was not under the condemnation of sin. He was, as a member of the Godhead, God on earth. His mission was to be the Savior of the world. As completely innocent being, He never deserved any of the suffering which he suffered. Yet, he suffered for the sins of all mankind. I don't think that a mere mortal could have gone through the suffering that Jesus went through. This suffering caused even God, the greatest of all to bleed from every pore of his body as were great drops of blood. It caused even him, to tremble because of pain and would not that he should have to suffer but he humbled himself before the Father and submitted to his will.
Luke 22:41-44
41 And he was withdrawn from them about a stone’s cast, and kneeled down, and prayed,
42 Saying, Father, if thou be willing, remove this cup from me: nevertheless not my will, but thine, be done.
43 And there appeared an angel unto him from heaven, strengthening him.
44 And being in an agony he prayed more earnestly: and his sweat was as it were great drops of blood falling down to the ground.
Doctrine and Covenants 19:16-19
16 For behold, I, God, have suffered these things for all, that they might not suffer if they would repent;
17 But if they would not repent they must suffer even as I;
18 Which suffering caused myself, even God, the greatest of all, to tremble because of pain, and to bleed at every pore, and to suffer both body and spirit—and would that I might not drink the bitter cup, and shrink—
19 Nevertheless, glory be to the Father, and I partook and finished my preparations unto the children of men.
Jesus as an infinite atonement who did no sin and was not deserving of any of the suffering he went through suffered the greatest of all injustices one could ever imagine. God the Father would have to recompense the Christ for all the injustice and suffering he bore. Not only for suffering alone but to the extent that he suffered. He and he alone was deserving of a great recompense for all the suffering and death that he suffered. His recompense from the Father was that he gained the right to forgive sin if others would only come unto him and repent of their sins. It was just to grant Jesus this great recompense. It was his recompense for all he went through unjustly. Now if a any man or woman would simply confess and forsake their sins or in other words repent and seek the forgiveness from Jesus, Jesus had the right to forgive the sins of the repentant soul. It is Christ's just reward to have the right to forgive any who repent and come unto him. He and he alone is the Savior of mankind. Only in and through the Christ are able to find forgiveness of sin and thus make it back to the kingdom of heaven.
Jesus upon dying a sinless death was able to take his life back again and resurrect from the dead. Not only was he granted the right to resurrect but he was also allowed to grant unto all that have taken on a mortal body this same resurrection. Thus all mankind will resurrect and become immortal beings. He truly is the Savior of all mankind and overcome death and hell for us all. Resurrection is a free gift to all but entrance into the kingdom of heaven requires that we repent and forsake our sins and follow Jesus and his commandments. If we do this, He will grant his grace upon us and we can also reunite with our Heavenly Father in his kingdom. Eventually all our memory will be restored and we will remember our premortal life and our faithfulness with God in the War in Heaven. Jesus had this same veil put over his mind but he learned to seek God and came to know the truth at a very early age. He did what no other person could do by living a perfect life in this world and thus he was worthy as God to be our Savior and show us the way the truth and the life. Jesus and all of us will resurrect and have an immortal body just as the Father himself has. We were all created in his image and likeness and will retain our immortal bodies forever and ever just as He and our Lord Jesus have.